PLaying my PS2 using my pc monitor

in theory you are right. You could plug the output of the PS2 into the TV in on a graphics card. However, unless this is to save having both a monitor and a tv in the room its pretty pointless. You would not gain an increased resolution becausea: the ps2 wouldn't be able to output a higher resolution than what the game was origionally intended for

b: the playstation would still think it was outputing to a TV so its resolution would remain static.

i tried that once with my tv card, andthe image was distorted, so i never did it again. A friend of mine has a VGA converter, its a box which plugs both the ps2 and the pc in which then plugs into the monitor and you need to switch a switch for the ps2 and switch it back for the pc.